No, you really don't.

You just need an IP address block that are accessable by both neighbors in a BGP peering session.

You don't need public IPs at your core, and it is not wise to use publicly accessable IP addresses
for your core routers.

But, I am NOT saying use RFC1918 private addresses :)

Use IP block that was allocated/assigned to you, set aside a small portion of it for transit space and
set up access-list at the edge to prevent access to routers by unauthorized parties (really, do random
people from the internet need to ping your core routers? not really.) <-- This is just one of the ways
to do it. You can use various other ways to accomplish same/similar BCP guideline, without resorting to
RFC1918 space.

It's better to get your own AS Number as you are connecting with two different ISPs. But if you can get
both of your ISPs to agree on a private AS for your network, and if you feel no problem with inconsistent
bgp path, and plus if you are confident you and your ISP won't leak private AS path, then private AS is
the way to go :)

-hc

-- 
Sincerely,
  Haesu C.
  TowardEX Technologies, Inc.
  WWW: http://www.towardex.com
  E-mail: haesu@...
  Cell: (978) 394-2867

On Fri, Jul 25, 2003 at 03:06:56PM +0200, Tomas Bonnedahl wrote:
> i was wondering if public routable address (in the core) is a requirement 
> when using bgp?
> 
> im really just interested in loadbalancing between the two operators 
> during normal operation and a failover to the other operator if one
> would fail. 
> 
> i do not have enough public address to cover the core, although i dont 
> know if the EGP routing would involve the core router and hence, perhaps
> dont need public addresses in the core.
> i know of ospf too, but read that it "should" be used under one AS entity, 
> not upstream, nor do i know what the ISPs policy is of using ospf to
> customers.
> 
> i dont own an ASN, the solution i was thinking about would be to have
> private address in the core and run iBGP/ospf there and use a private
> ASN and run BGP between my border routers and the isps access routers.
> 
> 
> i have a setup that looks like this:
> 
> 
> 		ISP A				 ISP B
> 		   |				   |
> 		   |				   |
>      	     [IBUS-BORDER1]		     [IBUS-BORDER2]
> 		    \				 /
> 		     \                          /
> 		      \			       /
> 		       \		      /
> 			\ --- [IBUS-CORE]--- /
> 				   |
> 				   |
> 			          LAN
> 
> 
> any hints/directions/bgp or ospf config samples/complete answers would be
> appricated.
> 
> 
> 
> thank you,
> tomas bonnedahl
> 
> ------------------------ANNOUNCEMENT---------------------------------
> ---------------------------------------------------------------------
>            ISPCON FALL 2003 - Santa Clara Convention Center
>      October 20-22 - The Definitive Event Wired and Wireless ISPs
>                             www.ispcon.com
> ----------------------------------------------------------------------
> ----------------------------------------------------------------------
> 
> 






------------------------ANNOUNCEMENT---------------------------------
---------------------------------------------------------------------
           ISPCON FALL 2003 - Santa Clara Convention Center
     October 20-22 - The Definitive Event Wired and Wireless ISPs
                            www.ispcon.com
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Replies

[isp-bgp] _newbie_ question regarding addresses and routing, Tomas Bonnedahl